Dynamo-electric machine.



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H. G. REIST. DYNAMO ELECTRIC MACHINE. APPLICATION FILED In 1s, 1909.

Patent ad Nov. 14, 1911.

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UNTTED sTATEs PATENT oEEroE.,

HENRY G'. REIST, OF SCHENECTADY, NEW YORK, ASSIGNOR TO ('rENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

DYNAMO-ELECTRIC MACHINE.

To all whom it may concern.'

Be it known that I, HENRY G. REIST, a citizen of the United States,residing at Schenectady, county of Schenectady, State of New York, haveinvented certain new and useful Improvements in Dynamo-ElectricMachines, of which the following is a specification.

My invention relates to dynamo electric machines, and more particularlyto field magnet structures Iin which the winding is distributed, asdistinguished from those structures which have definite or salientpoles. Such field magnet structures are known in the art as the smoothcore type. In such structures the central portion of the pole ismagnetized by all the turns on the pole, while outside of the centerportion it is magnetized only by the turns surrounding the outsideportion. In building these field magnets it is usual to distribute thewinding only in a small number of coils. They have been built heretoforewith a uniform airgap, and when the winding is distributed in a smallnumber of coils, the magnetic density on one side of a coil will beconsiderably less than on the other side of the same coil. In order toimprove the flux distribution, I shape the faces of the portions of thecore between the coils which make up the pole, so that they diverge fromthe periphery of the armature of the dynamo electric machine in adirection away from the centerof the pole, the divergence of the severalfaces being such as to produce a substantially sinusoidal distributionof flux. The core between the coils of the winding is preferably made upof members or coil holders placed in position as shown and described inthe patent to Sulzberger, No. 902,020, patented October 27, 1908.

Other features of novelty which characterize my invention are pointedout in the claims annexed to and forming a part of this specification.For a better understanding of my invention, however, reference may behad to the followingdescription taken in connection with theaccompanying drawing, in which- Figure 1 is an end elevation of arevolv` ing field magnet structure of a dynamo electric machineembodying my invention, with parts broken away and in section; Fig. 2 isa sectional view of the construction shown in Fig. 1; and Fig. 3 is anenlarged Specication of Letters Patent.

Application filed May 19, 1909.

Patent ed Nov. 14, 1911.

serial No. 496,973.

view of a portion of tl le same field magnet structure with the colsremoved for the sake of clearness.

Referring to the dr twings, 1 represents the spider carrying therevolving field magnet of a dynamo electri; machine. The core 2 o f thefield magnet is mounted on the spider 1 and in the particular machineillustrated is provided with ten polar portions. The windings of thefield magnet comprise similar sets of conductors, each 1n the form oftwo loops or coils 3 and 4, one set surrounding each polar portion. Thecoils 3 and 4 are ield in place by sets of coil holders or meml ers 8, 9and 10, made of magnetic material :,nd preferably laminated. Each polaror :ion of the field magnet structure is ma e 1' p of two members 9, twomembers 10, and :t central member l1. Both of the coils 3 and etsurround the members 10 and 11, which t gether form the central part ofthe pole. The members 9 are surrounded only by th e outside coil 4, andthe members 8 are no 'f surrounded by any of the coils. Therefor f, thecentral part of the pole is magnetized by twice the number of ampereturns that the members 9 are magnetized by, that is., of course, withthe ampere-turns of the c( ils 3 and 4 the same. The reluctance of thepath of the fiux depends mainly upon the air-gap, and is practicallyproportional t( it, and in order to get a sinusoidal distril ution ofiux, I have provided a variable tir-gap between the armature and thefield magnet, as is clearly seen in Fig. 3, in whicl` 12 represents alamination of the armatur s. This variable airgap is produced by-zonstructing the coil holders constitutingV 1he pole portions so thatthey diverge frorr the periphery of the armaturein a direction away fromthe center of the pole in the n anner hereinafter described. Themember.: 10 and 11, forming the center partof the role, diverge from theperiphery of the arm: ture from the center 13 of the poles toward eachside 14, so that the air-gap at each sido, is substantially double thatat the center o t thepole. The members 9 diverge from ;he periphery ofthe armature toward the :ides of the pole at a greater angle than tl:`at of the holders or members forming tht center part of the pole. Theportions of the members 9 which are toward the center )f the pole arelonger than the adjacent por :ions of the members sol 10. The air-gap atthe end 15 of the member 9 is the same as that at the center 13 olf thepole. The construction of the members, as described above, gives asmooth curve of flux distribution, which is substantially sinusoidal.

The coils 3 and 4 have end turns or connections 17. These end turnsmust' be supported so that they will be held rigidly and rmly in placeagainst the enormous centrifugal forces exerted thereon when the re-'volving field magnet is ro-tating at high speed. The end flange 18,which is keyed on the spider 1 and holds the laminations in place, hasarms 19 extending therefrom. The annular end cover 20 is fastened to thearms 19 in usual manner, and in accordance with my invention has itsoutsideperiphery tapered. The cylindrical cover 2l has a portion 22 ofits inside periphery tapered in the same direct-ion as the end cover,the tapered portion of the end cover and cylindrlcal cover cooperating,as shown in F 1g. 2. Flat pieces of metal 28 are bolted to the end coverand abut against and exert a lateral pressure upon the end of thecylindrical cover in order to stretch the cylindrical cover, and tocompress the end cover, so that the surfaces of the cylindrical coverand the end cover will remain in contact and the cylindrical cover willremain centered when the field magnet is revolving at high speed. Theend turns 17 are clamped in place against radial displacement by meansof the members 24 which are bolted to the cylindrical cover by means ofbolts 25, and thus the end turns are clamped between the members 24 andthe cylindrical cover 21.

I have illustrated my invention in connection with a ten-pole eld magnethaving two coils per pole, but it is evident' that it is not limited toany number of poles or any number of coils p'er pole. With a greaternumber of coils per pole the amount that each coil holder diverges fromthe periphery of the armature must' be modified accordingly.

I aim in the appended claims to cover all modifications which do notdepart from the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is,

1. In combination with the armature of a dynamo electric machine, a eldma et structure having a core, a' distributed vvlnding comprising aplurality of coils for' each po e, and members forming the polesarranged to space apart and secure in position said coils, the membersforming the center part of each pole diverging from the periphery of thearmature from the center of the pole toward each side, and the othermem; bers forming a part of the pole diverging from the periphery of thearmature toward the sides of the pole, the port-ions of said othermembers toward the center of the pole being longer than the adjacentportions of the members forming the center part of the po e. 2. Incombination with the armature of a dynamo electric machine, a fieldmagnet structure having a core, a distributed winding comprising aplurality of coils for each pole, and members arranged to space apartvand secure in position said coils, the mem- 'bers forming the centerpart of each pole diverging from the periphery of the armature from thecenter of the pole toward each jside, and the other members forming apart of the pole diverging from the periphery of -the armature towardthe sides of the pole at a greater angle than that of the membersforming the center of the pole, the portions of said other memberstoward the center of the pole being longer than the adjacent portions ofthe members forming the center part of the pole.

3. In a dynamo electric machine, a rotatable member comprising a core, awinding thereon having end turns or connections, an end cover andcylindrical cover for said end turns, said end cover and cylindricalcover having cooperating tapered portions which keep the cylindricalcover properly centered when the latter is subjected to centrifugalforcel 4. In a dynamo electric machine, a rotatable member comprising acore, windings thereon havin end turns or connections, an end cover anga cylindrical cover for said end turns, said end cover having itsoutside periphery tapered and said cylindrical cover having a portion ofits inside periphery tapered to cooperate with the taper on said endcover.

5. In a dynamo electric machine, a rotatable member comprising a core,windings thereon havin end turns or connections, an end cover an acylindrical cover for said end turns, said end cover having itsoutsideperiphery tapered and said cylindrical cover having a portion ofits inside periphery tapered to cooperate with the taper on said en dcover, and a member fastened to said end cover exerting a lateralpressure on said cylindrical cover.

In witness whereof, I have hereunto set my hand this 18th day of May1909.

HENRY G. HEIST. Witnesses:

BENJAMIN B. HULL, HELEN ORroRD.

copies ot this patent may be obtained for ve cents each, byv addressingthe "Commissionerof Patents,

Washington, D. 0.

